1. Field of the Invention
The present invention relates to a user interface upon selection of a plurality of dates by using a calendar on a display screen of a computer terminal or the like, and more particularly to a calendar display apparatus, a calendar display method and a computer program product.
2. Related Background Art
According to a well employed method as one of the prior art for selecting a plurality of dates from a calendar on the display screen of a computer terminal or the like, a calendar having buttons or soft keys for representing dates arranged on a display screen has been prepared and the buttons have been pushed by using a keyboard or a mouse to select the dates. Thus, all the selected dates have been listed up and the list has been displayed on a position except that of the calendar on the display, or the states or colors of the buttons or marks of the selected dates have been changed to express the selected states.
However, in the above described conventional method for displaying the list of all the selected dates on the position except that of the calendar on the display screen, a display area for displaying the list of the dates has always been necessary. Further, since all the selected dates are displayed in the list, an area in which the list is displayed has been undesirably increased. Still further, the position of a date button has been separate from that of the date list, so that an operation has been inconvenient and it has been difficult to understand the list at a glance.
Still further, according to another conventional method for expressing the selected states of the dates only by the states of the buttons on a calendar, if a month including the selected dates is not displayed when the month to be displayed is changed to another month, there will not be inconveniently understood which dates are selected. In this case, if many months are simultaneously displayed on the display screen to solve this issue, a large display area will be disadvantageously occupied on the display screen.
With the above described problems taken into consideration, it is an object of the present invention to provide a calendar display apparatus, a calendar display method and a computer program product having a date selecting function for completely displaying the selected states of all selected dates with a relatively small occupation of display area even when the selected dates are not accommodated in a displayed calendar month.
It is another object of the present invention to provide a calendar display apparatus, a calendar display method and a computer program product in which the selected states of all selected and displayed dates can be grasped and the selected states can be simply changed.
According to one aspect of the present invention, there is provided a calendar display apparatus, comprising: calendar display means for displaying at least one of calendars which display dates and a selected state of each date on a display screen; date selected state change instructing means for instructing the selected state of each date displayed to be changed; memory means for storing in a memory medium data indicating whether or not the date is selected; display period change instructing means for changing the display period of the calendar displayed on the display screen; deciding means for deciding whether or not the selected states of all the selected dates can be displayed on the displayed calendar on the basis of the data and the display period of the calendar; and date list display means for displaying the selected dates which cannot be displayed on the displayed calendar in the form of a list on a display area in the vicinity of the displayed calendar when it is decided that the selected states of all the selected dates cannot be displayed on the displayed calendar.
Further, according to another aspect of the present invention, there is provided a calendar display method comprising: a calendar display step of displaying at least one of calendars which display dates and the selected state of each date on a display screen; a date selected state change instructing step of instructing the selected state of each date displayed to be changed; a display period change instructing step of changing the display period of the calendar displayed on the display screen; a deciding step of deciding whether or not the selected states of all the selected dates can be displayed on the displayed calendar on the basis of data indicating whether or not the date is selected and the display period of the calendar; and a date list display step of displaying the selected dates which cannot be displayed on the displayed calendar in the form of a list on a display area in the vicinity of the displayed calendar when it is decided that the selected states of all the selected dates cannot be displayed on the displayed calendar.
Further, according to still another aspect of the present invention, there is provided a computer program product for a computer, comprising software code portions for performing the steps of: a calendar display step of displaying at least one of calendars which display dates and the selected state of each date on a display screen; a date selected state change instructing step of instructing the selected state of each date displayed to be changed; a display period change instructing step of changing the display period of the calendar displayed on the display screen; a deciding step of deciding whether or not the selected states of all the selected dates can be displayed on the displayed calendar on the basis of data indicating whether or not the date is selected and the display period of the calendar; and a date list display step of displaying the selected dates which cannot be displayed on the displayed calendar in the form of a list on a display area in the vicinity of the displayed calendar when it is decided that the selected states of all the selected dates cannot be displayed on the displayed calendar.
According to the present invention, when all the selected dates are not kept in the calendar of a displayed month, the list of the selected dates which cannot be represented on the calendar is displayed in a position near the calendar. Further, check boxes are added to individual dates in the list, so that the date which is not checked can be brought to a non-selected state.
As described above, even when all the selected dates are not kept in the calendar of the displayed month, the rest of dates appears on the list of the selected dates located in the vicinity of the calendar, an oversight can be avoided.
Further, since there are provided check boxes for avoiding the selected states in the list of the selected dates, the selected states can be changed like parts such as the check boxes adjacent to the dates on the calendar. Thus, an operation can be performed by seeing indications at a glance.
Still further, since the list of the selected dates appears when the selected dates cannot be represented on the calendar, it can be displayed only by using a minimum display area.
Furthermore, the display position of the list of the selected dates is changed depending on a selected date so that the contextual relation between the selected date and the displayed calendar month can be readily understood.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.